"Recently the Global Atheist Convention website suffered a DDOS (Distributed Denial of Service) attack, which caused the Global Atheist Convention and the Atheist Foundation of Australia websites to be taken offline," says the AFA.

"While we do not have enough information to confirm the source or reason for the attacks, they came in the wake of news that The Rise of Atheism Global Atheist Convention has already sold 1,000 tickets and will be the largest gathering of atheists and other freethinkers in Australia’s history. This may have been not just an attack on atheism, but an attack on freedom of speech."

The event is to be held in Melbourne next March, with speakers including Richard Dawkins, author of The God Delusion.